1. Field of the Invention
The invention relates to a pump for conveying flowable, in particular paste-like materials, such as for example mud or sludge, oil and chemical industry materials or materials which harden or set such as for example cement mix or plaster of Paris mix, concrete or the like.
2. Discussion of the Prior Art
For conveying flowable, in particular paste-like materials, there are known in the art screw or worm conveyers, hose pumps and so-called impeller pumps. These pumps are disadvantageous for several reasons. On the one hand, they are subject to wear and tear and not only at higher conveying pressures, for example 3 bar or more, but also because of wear and tear caused by the material itself and by contamination of the material. On the other hand, lump or clump-like contamination in the material to be conveyed can damage the pump elements, block the pump and disable the pump. A further disadvantage is found in that the known pumps have a relatively large pump filling volume, which leads to large volume losses in particular when pumping materials which harden or set.